The present document is based on Japanese Priority Document JP 2001-161980, filed in the Japanese Patent Office on May 30, 2001, the entire contents of which are incorporated herein by reference to the extent permitted by law.
1. Field of the Invention
The present invention relates to an antenna apparatus and to a transmission/reception apparatus having such an antenna apparatus. More specifically, the present invention relates to an antenna apparatus capable of attaining a required sensitivity for communication even when a transmission/reception apparatus having such an antenna apparatus is downsized, and the housing for the antenna apparatus is thereby reduced in size.
2. Description of the Related Art
In recent years, there has been a trend towards smaller, thinner and lighter communication devices. This trend is particularly marked in transmission/reception devices for mobile communication, and therefore the need for downsizing antennas used for such devices has become unavoidable. A typical example of a small-size antenna is the patch antenna.
FIG. 7A through FIG. 7C show the structure of a patch antenna 10, wherein FIG. 7A is a plan view, FIG. 7B is a cross-sectional view through section Axe2x80x94A of FIG. 7A and FIG. 7C is a side view of FIG. 7A observed from the right.
In FIG. 7A-FIG. 7C, the patch antenna 10 is positioned on an earth circuit board 1, and comprises a dielectric material 3, a radiator element conductor pattern 4a formed on the top surface of the dielectric material 3, an impedance matching conductor pattern 4b, an earth conductor pattern 7 formed on the bottom surface of the dielectric material 3, and a power feeding pattern 8 for feeding power to the radiator element conductor pattern 4a. The earth circuit board 1 is constructed by adhering a copper plate 1a and an insulation board 1b together.
Further, the impedance matching conductor pattern 4b includes an impedance matching conductor pattern section formed on the same surface as the radiator element conductor pattern 4a, as well as an earth conductor pattern section formed along a side surface of the dielectric material 3 in a direction perpendicular to the copper plate 1a of the earth circuit board 1. The earth conductor pattern section of the impedance matching conductor pattern 4b is connected to the copper plate 1a, and, along with the power feeding pattern 8, constitutes a power feeding section as a counterpart earth terminal to the power feeding pattern 8.
In addition, the radiator element conductor pattern 4a and the impedance matching conductor pattern 4b constitute an antenna pattern section 4. The antenna pattern section 4 and the dielectric material 3 constitute an antenna section 2.
Power is fed to the patch antenna 10 by connecting the radiator element conductor pattern 4a to a center conductor of a coaxial cable 6, and the copper plate 1a of the earth circuit board 1 to an outer conductor of the coaxial cable 6.
FIG. 8A and FIG. 8B are configuration diagrams of a transmission/reception apparatus 20. FIG. 8A is a plan view, and a speaker 21, a display 22, dial buttons 23 and a microphone 24 are provided. FIG. 8B is a schematic cross-sectional view through section Cxe2x80x94C of FIG. 8A, and the patch antenna 10 shown in FIGS. 7A through 7C is attached to the transmission/reception apparatus 20 in the direction of its length by way of some appropriate attaching means not shown in the figures. In this type of a transmission/reception apparatus, because the transmission/reception apparatus 20 has a sufficient length, the earth circuit board 1 of the patch antenna 10 can be elongated, and thus a predefined sensitivity can be attained relatively easily.
FIG. 9A and FIG. 9B are configuration diagrams of a folding transmission/reception apparatus 30. FIG. 9A is a plan view, showing that the folding transmission/reception apparatus 30 is structured so as to be foldable such that, when folded, a dial button side 33 located on one side of a folding section 31 faces a display side 32 located on the other side of the folding section 31. FIG. 9B is a schematic cross sectional view through lines Dxe2x80x94D of FIG. 9A showing the folding transmission/reception apparatus 30 as folded. The patch antenna 10 shown in FIGS. 7A through 7C is provided on the dial button side 33 of the folding transmission/reception apparatus 30 by way of some appropriate means not shown in the diagram. This type of transmission/reception apparatus is widely used and popular for its stylish design, and for its handiness as it can be folded and stored in limited spaces such as chest pockets.
However, when the body of the transmission/reception apparatus described above (foldable or not) is downsized, the length of the body is reduced, and thus, a predetermined sensitivity for the bandwidth in use becomes unattainable. For this reason, in the worst case, the transmission/reception apparatus becomes unable to communicate due to inferior sensitivity. In addition, when kept in a chest pocket, for example, there is also the problem that the apparatus is prone to falling out of the chest pocket because it has no means by which it can attach itself to the pocket.
The present invention is proposed in view of such problems described above. An aspect of the present invention is to configure an antenna which can be housed inside a transmission/reception apparatus, and is capable of attaining a predetermined sensitivity for a frequency band in use, even if the transmission/reception apparatus is downsized, thereby making the antenna housing space smaller.
Another aspect of the present invention is to provide a transmission/reception apparatus having such an antenna.
Yet another aspect of the present invention is to prevent the transmission/reception apparatus having the antenna described above from falling out from, for example, a pocket on clothing when it is carried around or used while stored therein.
An antenna apparatus according to an embodiment of the present invention is characterized by its capability of securing a predetermined earth pattern length which is achieved by connecting an earth circuit board having antenna circuitry mounted thereon to a second earth circuit board using a flexible conduction means when the antenna apparatus is in use.
A transmission/reception apparatus according to an embodiment of the present invention is characterized by its possession of an antenna apparatus which is capable of securing a predetermined earth pattern length which is achieved by connecting an earth circuit board having antenna circuitry mounted thereon to a second earth circuit board using a flexible conduction means when the antenna apparatus is in use.
A transmission/reception apparatus according to another embodiment of the present invention is the transmission/reception apparatus described above wherein the earth circuit board having antenna circuitry mounted thereon and the second earth circuit board combined together satisfy a predetermined earth pattern length by having the second earth circuit board moved outward from a body of the transmission/reception apparatus.
A transmission/reception apparatus according to another embodiment of the present invention is the transmission/reception apparatuses described above, wherein the second earth circuit board has a clip means for clipping the transmission/reception apparatus onto, for example, a pocket.
According to the present invention, even if a transmission/reception apparatus is downsized, and a housing space for an antenna becomes smaller, the antenna can be housed in a body of the transmission/reception apparatus, while still being able to secure an earth pattern length required to use the transmission/reception apparatus, and there is no danger of lowering the transmission/reception sensitivity.
According to the present invention, a transmission/reception apparatus which can house an antenna and whose transmission/reception sensitivity is not lowered even if the transmission/reception apparatus is downsized, and a housing space for the antenna thereby becomes smaller can be provided.
According to the present invention, a folding transmission/reception apparatus can secure an earth pattern length required for transmission/reception even in its portable state (folded), and thus the transmission/reception sensitivity does not become lower even while it is being carried in a pocket on clothing, for example.
According to the present invention, because a clip means is provided for attaching the transmission/reception apparatus to pockets on clothing, for example, the danger of dropping or losing the transmission/reception apparatus while carrying it or while it is standing by for an in-coming call is reduced.